Particle Flocker Attributes

Each ParticleFlocker node exposes a number of attributes which control the behaviour of the flocking system.

Simulation Accuracy

This attribute ranges from 0-1 and controls the accuracy of the simulation.

The system sets the accuracy by intermittently skipping simulation steps. The Simulation Accuracy attribute controls the probability that a particle will perform its simulation step on each frame. So for example a value of 0.5 means that there is a 50% probability that a particle will perform a simulation calculation on each frame whereas a value of 1 means that particles will always perform the simulation calculations.

Reducing the Simulation Accuracy attribute will improve the simulation performance in Maya and can be used to speed up playback when working with complex scenes or very high numbers of particles. However it should also be noted that reducing the accuracy of the simulation will result in more particle or obstacle intersections and less exact steering behaviour.

Number of Neighbours

This attribute sets the number of neighbouring particles that each particle will react to. For example if this value is set to 2, each particle will consider its 2 nearest neighbours during the simulation.

Flocking systems work because individual members of the flock will react to other flock members. Without this “awareness” of their neighbours, particles would not be able to move as a flock.

It is important to note that determining the nearest neighbours of a particular particle is quite an expensive (slow) operation and so the higher this number, the slower the simulation.

Boid Separation

This attribute controls how far apart individual particles will attempt to stay away from one another.

This value is specified in Maya’s current UI units, meaning that the value will vary depending on the units Maya is currently working in (i.e. centimeters, meters etc.)

Obstacle Separation

This attribute controls how far particles will attempt to stay away from the surface of obstacles and containers. See Obstacles for details on how this is used.

This value is specified in Maya’s current UI units, meaning that the value will vary depending on the units Maya is currently working in (i.e. centimeters, meters etc.)

Maximum Speed

This attribute sets the maximum speed at which particles are able to travel.

Because particles are controlled by simple physical forces, the higher the speed of a particle the higher the force required to make them change direction.

This value is specified in Maya’s current units per second, meaning that the value will vary depending on the units Maya is currently working in (i.e. centimeters per second, meters per second etc.)

Maximum Force

This attribute sets the maximum force that can be applied to a particle in order to steer.

This applies to all particle steering, including standard flocking behaviour, steering behaviour and obstacle avoidance.

This value is specified in Maya’s current UI units per second per second, meaning that the value will vary depending on the units Maya is currently working in (i.e. centimeters per second per second, meters per second per second etc)

Boid Separation Urge

This attribute controls the strength of the particle’s Separation urge.

A value of 1 means the particle will fully perform this standard behaviour while a value of 0 means this behaviour will be ignored. You may also use values greater than 1 to boost the urgency of this behaviour.

Flock Centring Urge

This attribute controls the strength of the particle’s Flock Centring urge.

A value of 1 means the particle will fully perform this flocking behaviour, while a value of 0 means this behaviour will be ignored. You may also use values greater than 1 to boost the urgency of this behaviour.

Velocity Matching Urge

A value of 1 means the particle will fully perform this flocking behaviour, while a value of 0 means this behaviour will be ignored. You may also use values greater than 1 to boost the urgency of this behaviour.